Refine the definition of the toc() delta argument

Author: jsiirola

pyomo/common/tests/test_timing.py

@@ -168,7 +168,7 @@ def test_TicTocTimer_tictoc(self):
         with capture_output() as out:
             ref = time.perf_counter()
             total = timer.toc(delta=False)
-        self.assertAlmostEqual(ref - abs_time, total, delta=RES)
+        self.assertAlmostEqual(ref - start_time, total, delta=RES)
         self.assertRegex(
             out.getvalue(),
             r'\[    [.0-9]+\] .* in test_TicTocTimer_tictoc'

pyomo/common/timing.py

@@ -205,7 +205,7 @@ def tic(self, msg=_NotSpecified,
                 class was constructed). Note: timing logged using logger.info
 
         """
-        self._lastTime = default_timer()
+        self._lastTime = self._loadTime = default_timer()
         if msg is _NotSpecified:
             msg = "Resetting the tic/toc delta timer"
         if msg is not None:
@@ -225,9 +225,9 @@ def toc(self, msg=_NotSpecified, delta=True,
                 called this method; if msg is None, then no message is
                 printed.
             delta (bool): print out the elapsed wall clock time since
-                the last call to :meth:`tic` or :meth:`toc`
-                (``True`` (default)) or since the module was first
-                loaded (``False``).
+                the last call to :meth:`tic` (``False``) or since the
+                most recent call to either :meth:`tic` or :meth:`toc`
+                (``True`` (default)).
             ostream (FILE): an optional output stream (overrides the ostream
                 provided when the class was constructed).
             logger (Logger): an optional output stream using the python
@@ -254,6 +254,9 @@ class was constructed). Note: timing logged using logger.info
                 msg = "[+%7.2f] %s\n" % (ans, msg)
         else:
             ans = now - self._loadTime
+            # Even though we are reporting the cumulative time, we will
+            # still reset the delta timer.
+            self._lastTime = now
             if msg is not None:
                 msg = "[%8.2f] %s\n" % (ans, msg)